Finding the Third Proportional to 19,639 and 42,390.75

Step by Step Solution

1. Step 1: Write the proportion equation
   19,639 : 42,390.75 = 42,390.75 : x
2. Step 2: Convert to fraction form
   19,639/42,390.75 = 42,390.75/x
3. Step 3: Cross multiply
   19,639x = 42,390.75 × 42,390.75
4. Step 4: Simplify right side
   19,639x = 1,796,975,685.56
5. Step 5: Solve for x
   x = 1,796,975,685.56/19,639
6. Step 6: Final answer
   x = 91,500.37